Method for centering a valve

ABSTRACT

A vascular guidewire introducer device ( 10 ) having a needle ( 52 ), a bulb ( 16 ), and a valve subassembly ( 100 ) through which a guidewire ( 14 ) is insertable for vascular guidewire insertion into a blood vessel ( 12 ) of a patient. The valve subassembly ( 100 ) includes a proximal fitting ( 102 ), a proximal cap ( 106 ), and a valve arrangement ( 104 ) disposed within a valve seat ( 118 ) defined by one of the fitting and the cap. The valve arrangement includes distal and proximal disc-shaped valve members ( 122,126 ) having centered slits ( 124,128 ) therethrough, and a spacer ( 130 ) disposed between the valve members. A method is disclosed for precisely centering the slits of the valve members during assembly and for retaining the valve members in their precisely centered positions in the valve seat. The valve arrangement permits use with a wide range of guidewire diameters.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional application of U.S. application Ser.No. 12/469,839 filed May 21, 2009, which claims priority from U.S.Provisional Application Ser. No. 61/055,005, filed May 21, 2008.

FIELD OF THE INVENTION

This relates to the field of medical devices and more particularly tovascular guidewire introducer devices.

BACKGROUND OF THE INVENTION

Generally, to insert any catheter into a blood vessel, the vessel isidentified by aspiration with a long hollow needle in accordance withthe well known Seldinger technique. In its simplest application, aneedle, with a syringe attached, is introduced into the patient. Whenblood enters the syringe, it provides visual indication that the vesselhas been found; the syringe is then disconnected from the needle and athin guidewire is then introduced into the needle and into the interiorof the vessel. Commonly, upon disconnection of the syringe from theneedle, bleeding can occur from the needle and onto the operative field,or air can be aspirated into the vessel if the patient inspires whilethe needle is not sealed prior to and during introduction of theguidewire into the needle. Blood on the operative field exposes thecaregivers to contamination with blood-borne pathogens, andintravascular air can result in vascular occlusion and injury or death.The introducer needle is then removed from the patient and slid over theguidewire proximal end, leaving the distal end portion of the guidewirethat has been inserted into the vessel within the vessel and theopposing end of the guidewire projecting beyond the surface of the skinof the patient.

At this point, several options are available to a physician for catheterplacement. The simplest is to pass a catheter into the vessel directlyover the guidewire. The guidewire is then removed, leaving the catheterin position within the vessel. However, this technique is only possiblein cases where the catheter is of relatively small diameter, made of astiff material, and not significantly larger than the guidewire. Forexample, this technique may be used to insert small single-lumen ordual-lumen catheters into a patient. If the catheter being inserted issignificantly larger than the guidewire, a dilator catheter made ofstiff material is passed over the guidewire to enlarge the hole. Thedilator catheter is then removed, and the catheter is then passed overthe guidewire into the vessel after which the guidewire is then removed.

One type of syringe and needle for use in introducing a guidewire intothe vasculature is disclosed in U.S. Pat. No. 5,045,065. The syringeassembly includes a syringe barrel to which a distally projecting needlecan be attached. The barrel contains a fluid chamber, and a tubeattached to the distal base of the barrel projects proximally into thechamber and includes a proximal side hole within the barrel. A two-partplunger is slidable within and along the chamber and contains acentrally located guidewire passage therethrough; the proximal end ofthe tube also extends into the plunger's guidewire passage. A valveassembly is contained within the plunger near its proximal end andincludes a pair of axially staggered valves within the plunger andtraversing the guidewire passage to prevent fluid flow therethrough fromthe needle, or air passing therethrough from the open plunger proximalend, while permitting insertion therethrough of the guidewire.

In use, regarding the device of U.S. Pat. No. 5,045,065, the vessel isidentified by first inserting the distal tip of the needle below theskin. The plunger is then withdrawn proximally to develop negativepressure within the barrel of the syringe. Traction on the plunger isthen maintained while the syringe is advanced into the vessel. Upon theneedle's distal tip entering the blood vessel, blood is aspirated intothe syringe barrel through the side hole of the tube within the barrel'schamber. Once the vessel is identified, the plunger is advanced andaspirated blood is flushed back into the vessel. The guidewire is theninserted through the plunger and the valve assembly, through theguidewire passage tube in the barrel, through the needle and into thevessel of the patient.

Although the device of U.S. Pat. No. 5,045,065 represents a significantimprovement over the standard syringe/needle technique as taught bySeldinger, its use has several drawbacks: (1) the plunger must beretracted as the syringe is advanced in the opposite direction; (2) thesyringe is heavy and once the needle is in the vessel it must besupported by one hand of the practitioner, allowing only one hand forpreparation and introduction of the guidewire; (3) even with the plungerseated within the barrel of the syringe, the distance from the guidewireentry into the plunger to the vessel is relatively long, and anyinadvertent movement of the syringe during the procedure can dislodgethe needle from the vessel; and, (4) negative pressure created by thepractitioner as the syringe is advanced is operator-dependent and eventhough non-coring needles are used, if the negative pressure is toohigh, subcutaneous fat can be pulled into the needle causing occlusionand preventing blood entry into the barrel even when the needle entersthe vessel.

In U.S. Pat. No. 6,277,100 is disclosed an introducer device thatincludes an integral aspiration bulb and no plunger, which disclosure isincorporated hereinto by reference. Such a closed system vascularguidewire introducer device is illustrated in FIGS. 1 and 2 hereof. Thedevice includes a transparent flexible valved bulb to which a needle isremovably attached at its distal end. A conduit extends from theproximal device end and through the bulb, and is aligned with theneedle's channel, thus defining a passageway extending through thedevice for eventual insertion of a guidewire therethrough into thevasculature. The conduit includes a proximal valve traversing theconduit at the proximal end of the bulb, the valve being openable by theguidewire being inserted therethrough but otherwise remaining closed toseal the conduit. The device is operated by first compressing the bulb.The needle is then inserted under the skin and the pressure on theflexible bulb is released creating constant negative pressure on theneedle. The device is then advanced into the blood vessel, and once theneedle tip enters the blood vessel, blood is aspirated into the bulb bythe negative pressure created on the flexible bulb. A guidewire is thenintroduced and passed through the valve contained within the bulbassembly and advanced into the vessel. The bulb and needle are thenremoved leaving the guidewire within the vessel. The advantages of thisdevice are as follows: (1) the negative pressure necessary foraspiration of blood is not operator dependent but rather is maintainedby the bulb once it is compressed and released; (2) the device islightweight and in most adults does not require the practitioner tosupport it once the vessel is identified; and, (3) the length of thedevice is shorter than the syringe/needle combination described in theprevious patent. Therefore, with these advantages, there is lesslikelihood of losing cannulation during the procedure.

Guidewires usually are tightly coiled wires that are known for theirflexibility, and they range in size from about 0.018 in (0.457 mm) to0.045 in (1.143 mm), with the smaller size guidewires being moreflexible than the larger sizes. While the valve of the above-referencedbulb introducer permits passage of guidewires of most sizes, the valvehas proven to be relatively stiff, and too often resists the insertiontherethrough of guidewires of very small size, such as 0.018 in, whichare known to be highly flexible. Further, even after insertion, thevalve compresses against the guidewire to establish noticeable friction,or drag, that inhibits the practitioner from reliance on delicatetactile feel of the guidewire's contact with the vessel walls of thepatient's vasculature.

It is desired to provide a valve or valve arrangement for a guidewireintroducer device that facilitates smooth insertion of a guidewirethrough the valve or valve arrangement with minimal friction or drag andwithout snagging or damaging the valve, and permitting both advancementor retraction of the guidewire therethrough during guidewire placement,with minimal friction or drag and without snagging or causing valvedamage. The valve must also reseal prior to insertion to maintain thenegative pressure created when the bulb is compressed prior to insertionunder the skin and then released after insertion.

It is also desired to provide the guidewire introducer device with sucha valve for use with, and to permit successful insertion through thevalve assembly of, especially small diameter guidewires, such as 0.018in (0.457 mm), as well as larger diameter guidewires, such as 0.045 in(1.143 mm).

It is further desired to permit enhanced tactile feel transmitted by theguidewire to the practitioner, that is desired by the practitionerduring guidewire placement through the vasculature, again especiallywith very small diameter guidewires.

BRIEF SUMMARY OF THE INVENTION

Briefly, the present invention is an introducer device for vascularguidewire insertion, having a valve arrangement that permits andfacilitates smooth guidewire insertion therethrough with minimalfriction, without snagging and without valve damage. The introducerdevice includes a bulb mounted on distal and proximal fittings. A needleis mounted to the distal fitting to extend distally from the bulb. Theintroducer device of the present invention includes a conduit thatextends integrally from the proximal fitting through the bulb to thedistal fitting and is aligned with the passageway of the needle, with anopening into the bulb at the distal fitting for blood aspiration intothe bulb. A proximal cap is affixed to the proximal fitting and retainsa valve arrangement within a valve seat defined by at least one of theproximal cap and the proximal fitting, the valve arrangement beingnormally closed but permitting insertion therethrough of a guidewireupon its insertion into an entrance of the proximal cap.

The valve arrangement of the present invention comprises a single valvesuch as of elastomeric material, or more preferably a pair of valvesspaced apart from each other by a spacer, all of which are securedwithin the valve seat. Preferably, the or each valve is a thin disc witha slit partially traversing the disc at its center. Also, preferably,the transverse disc-adjacent surfaces of the proximal fitting, thespacer and the proximal cap include small funnel-shaped depressionsthereinto to facilitate insertion of the guidewire through the deviceand also provide clearance for deflection of slit-adjacent lips of thevalve member or members during guidewire insertion, and facilitatesadvancement of the guidewire and retraction thereof, if necessary.

Precision centering of the valve members with respect to the axis of theintroducer device is preferable, such that the or each slit preciselyintersects the axis. Centering may be performed such as with a centeringtool prior to firmly fixing the respective positions of the valvemembers within the device, as follows: the valve members are placed inthe valve seat and are of a smaller diameter than the valve seat topermit incremental transverse adjustment, and the spacer is alsopositioned in the valve seat between the valve members; prior to fullypositioning the proximal cap onto the proximal fitting, a mandrel of thecentering tool is inserted through the proximal cap, through the slit ofthe proximal valve member, through the axial bore of the spacer andthrough the slit of the distal valve member and into the passageway ofthe proximal fitting, which precisely centers the valves in the valveseat; with the centering tool in its inserted position, the proximal capis urged completely onto the proximal fitting, compressing the valvemembers between the adjacent surfaces of the proximal fitting, thespacer and the proximal cap, and the proximal cap is bonded or welded inposition, or otherwise permanently affixed to the proximal fitting; thecentering tool is then withdrawn.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate the presently preferredembodiments of the invention, and, together with the general descriptiongiven above and the detailed description given below, serve to explainthe features of the invention. In the drawings:

FIG. 1 is a longitudinal elevation view of a PRIOR ART guidewireintroducer device extending into a blood vessel, with a guidewireextending therethrough;

FIG. 2 is a longitudinal cross-sectional, exploded view of the PRIOR ARTintroducer device of FIG. 1 taken along lines 2-2 with the guidewireremoved;

FIG. 3 is a longitudinal cross-sectional view of the proximal endassembly of an introducer device containing the valve arrangement of thepresent invention;

FIG. 4 is an exploded isometric view of the proximal end assembly ofFIG. 3;

FIG. 5 is an elevation view of the valve separator of the presentinvention;

FIGS. 6 and 7 are enlarged views of the valve seat of the presentinvention illustrating the insertion of a guidewire through a valvemember, with FIG. 6 showing the valve slit region and FIG. 7 showing aguidewire being inserted through the valve slit;

FIG. 8 is an isometric view of the proximal end assembly of the presentinvention, with a valve centering tool positioned to be insertedthereinto for centering the valves;

FIGS. 9 and 10 are longitudinal cross-sectional views of the proximalend assembly showing the centering tool holding the valves transverselycentered before and after the proximal end cap is secured to theproximal fitting to compress the centered valves; and

FIG. 11 is a longitudinal cross-sectional view of the proximal endassembly showing the valves fully centered and the centering toolremoved.

DETAILED DESCRIPTION OF THE INVENTION

In the drawings, like numerals indicate like elements throughout.Certain terminology is used herein for convenience only and is not to betaken as a limitation on the present invention. The terms “distal” and“proximal” refer, respectively, to directions closer to and away from apatient's blood vessel. The terminology includes the words specificallymentioned, derivatives thereof and words of similar import. Theembodiments illustrated below are not intended to be exhaustive or tolimit the invention to the precise form disclosed. These embodiments arechosen and described to best explain the principle of the invention andits application and practical use and to enable others skilled in theart to best utilize the invention.

As shown in FIGS. 1 and 2, generally, a PRIOR ART guidewire introducerdevice 10 is used to aspirate a blood vessel 12 (shown in phantom), andinsertion of a guidewire 14 into the blood vessel. The guidewire may bestraight or have a J-shaped insertion end to prevent the end of theguidewire 14 from catching on the inner wall of the blood vessel 12. Aflexible bulb 16 of transparent material includes a first end 18, asecond end 20 and an interior cavity 22. A distal fitting 28 is locatedon the first end 18 of the bulb and includes an internal chamber 30, andfirst and second axially aligned passageways 32,34 in fluidcommunication with the chamber 30. A third passageway 36 is provided inthe distal fitting 28 in fluid communication between the chamber 30 andthe interior cavity 22 of the bulb 16.

An introducer needle 52 has distal and proximal ends 56,54 and a lumen58, and the distal end 56 is sharpened to allow for penetration of bloodvessel 12, as shown in FIG. 1. The proximal end of the needle isconnected to the fitting 28 in the first passageway 32 to be in fluidcommunication with the lumen 58, and chamber 30 is funnel-shaped tofacilitate guidewire insertion into the proximal end of lumen 58.

The PRIOR ART valve subassembly includes a proximal fitting 72, aproximal cap 90 and a valve assembly 70. Proximal fitting 72 is affixedwithin the second end 20 of the bulb 16 and includes a conduit portion60 extending integrally distally through the bulb to conclude in a plug40 seated in chamber 30. A passageway 66 extends through the proximalfitting 70 and the conduit portion 60 to open into second passageway 34and the internal chamber 30 whereat it is in alignment with lumen 58 ofthe needle. Plug 40 includes one or more axial channels located radiallyoutwardly of passageway 66 that provide fluid communication betweenchamber 30 and interior cavity 22 of bulb 16.

Proximal cap 90 is affixed to proximal fitting 72 and secures in a valveseat 73 defined therebetween, a valve assembly 70. Cap 90 includes afunnel-shaped entrance 92 and an axial bore 94 aligned with the conduitpassageway 66, and the valve assembly 70 is disposed to traverse theregion between the axial bore 94 and passageway 66. The valve assembly70 of the PRIOR ART shown in FIGS. 1 and 2 comprises a seal 74 and aseal support 84, where the seal has a raised portion 76 around thecenter of the proximal surface, a depression 78 therewithin, and a slit80 across the center of the depression. Seal support 84 includes arecess 86 complementary to raised seal portion 76, and has a centralopening 88 aligned with slit 80 such that a guidewire 14 is insertablethrough the central opening 88 and slit 80 to extend from the axial bore94 to enter the conduit passageway 66 and thus into the chamber 30 ofthe distal fitting 28 and into the lumen 58 of the needle.

The present invention is shown generally in FIGS. 3 and 4, and comprisesa valve subassembly 100 for a guidewire introducer device, that includesa proximal fitting 102, a valve arrangement 104 and a proximal cap 106.Proximal fitting 102 has a conduit portion 108 extending to a distalplug portion 110, and a passageway 112 therethrough from a proximalflange 114; conduit and plug portions 108,110 can be those of the PRIORART conduit portion 60 and plug 40. Proximal cap 106 includes anentrance 116 that is in alignment with conduit passageway 112. Valvearrangement 104 is disposed within a valve seat 118 and is securedtherein by proximal cap 106, and the valve seat may be defined in one ofthe proximal fitting and the proximal cap, and is shown as being definedin the proximal flange 114 of the proximal fitting 102. The proximalfitting and the proximal cap have transverse valve-adjacent surfacesbounding the valve seat to compress the valves axially upon completeassembly. The proximal flange is received into a distal recess 120 ofproximal cap and affixed thereto, after the valve arrangement has beenassembled and centered in valve seat 118.

Valve arrangement 104 preferably includes a pair of valve members122,126 each having a central opening therethrough, such as a slit124,128 traversing a central portion that permits insertion therethroughof a guidewire (see FIG. 1). It is desirable that the valve members areso positioned in the valve seat that the slits 124,128 are relativelyangularly offset (see FIG. 4). Preferably, each valve member 122,126 isa thin flat disc of elastomeric material such as polyisoprene. Betweenvalve members 122,126 is a spacer 130 of relatively noncompressiblematerial having a central funnel-shaped depression 132 into each of theproximal surface 134 and the distal surface 136, each defining anentrance into an axial bore 138 that extends through the spacer betweenthe depressions (see FIG. 5). The central funnel-shaped depression 132is adapted to facilitate capture of the tip of the guidewire and directit into the axial bore 138, similarly to the funnel-shaped depressioninto the body of proximal fitting 102 about the entrance to passageway112 (FIG. 3). Additionally, preferably, both the proximal and distalspacer surfaces 134,136 have defined thereon respective compressionrings 140 each comprising a sharp ridge surrounding the respectivedepressions 132 that will, upon final assembly of subassembly 100,become pressed into the adjacent surfaces of the respective valvemembers 122,126 to assuredly retain the valve members precisely centeredwithin valve seat 118. Also, preferably, side surfaces of spacer 130have incremental distal and proximal draft angles, defining a centralapex 142 that is force-fittable within the valve seat 118 by assuredengagement with the valve seat sidewalls resulting in centering of thespacer transversely within valve seat 118 (as well as having previouslyfacilitated removal of the molded spacer from its mold cavity).

As depicted in FIGS. 6 and 7, the funnel-shaped depressions 132 of theproximal cap 106, the spacer 130 and the proximal fitting (not shown)extending to passageway 138 preferably are so sized and dimensioned asto provide a clearance and be unengaged by the deflected slit-adjacentvalve portions during insertion, advancement and retraction of theguidewire through the slits of the valves, so that the valve arrangementmay accommodate a range of guidewire sizes. In this way, the valve discsare not compressed and therefore do not apply pressure to the guidewireduring axial movement thereof through the slits. Optionally, however,the funnel-shaped depressions could be shaped and dimensioned to preventoverdeflection of these valve portions.

The present invention is useful with guidewires ranging in size from0.018 in (0.457 mm) to 0.038 in (0.965 mm) or more, with either astraight distal tip or a J-shaped tip. For very small diameterguidewires having a J-shaped tip, optionally a cannula (not shown) maybe used to extend through the valve or valves to assure that theJ-shaped distal guidewire tip is held straightened to pass through theslit or slits of the valve or valves.

FIGS. 8 to 11 illustrate the centering procedure for centering the valvemembers 122,126 within the valve seat 118, which is preferable tooptimize the benefits of easy, low friction, nonsnagging, nondamaginginsertion and retraction of a guidewire through the slits 124,128. Acentering tool 200 is utilized having a handle 202 and a mandrel 204extending therefrom sufficiently small in diameter as to be insertedinto the entrance 116 and the axial bore of proximal cap 106 and throughthe slits 124,128 of the valve members 122,126 and axial bore 138 of thespacer 130 and then to be eventually withdrawn therefrom, withoutcausing damage to the valves.

FIG. 9 depicts a first stage of the centering procedure during which theproximal cap 106 is not fully urged onto the proximal flange 114 of theproximal fitting 102 when the centering tool 200 is insertedtherethrough, allowing the valve members 122,126 and the spacer 130 tobe relatively loosely disposed in valve seat 118. Preferably, thediameters of the valve members 122,126 are less than the inner diameterof valve seat 118 thus allowing incremental transverse movement of thevalve members during centering. Passage of mandrel 204 through the slits124,128 of the valve members 122,126 perforce centers the relativelyloose valve members within valve seat 118, or more accurately stated,centers the slits such that each slit 124,126 traverses a point alignedwith the center of at least the conduit passageway 112.

In the second stage shown in FIG. 10, the proximal cap 106 withcentering tool 200 are together urged fully onto proximal flange 114 ofproximal fitting 102, while the mandrel 204 maintains the valve members122,126 precisely centered. Compression rings 140 of the proximal anddistal surfaces 134,136 of spacer 130 now are pressed into the adjacentsurfaces of the valve members, thus firmly securing the valve members intheir precisely centered positions while proximal cap 106 is bonded orultrasonically welded onto proximal fitting 102. Optionally, similarcompression rings may be provided on the valve-adjacent surfaces ofproximal fitting 102 and proximal cap 106, for similar reasons.

Centering tool 200 is then removed from the subassembly, with thecentered and compressed valve members 122,126 held securely in positionduring tool removal and thereafter, as seen in FIG. 11. With slits124,128 now precisely traversing points axially aligned with the centersof the conduit passageway 112 and axial bore 138 of spacer 130 and theaxial bore of proximal cap 106, a guidewire (see FIG. 1) can now beinserted therethrough with ease. Proximal fitting 102 and proximal cap106 preferably include funnel-shaped centered depressions 144,146aligned with similar depressions 132 of spacer 130 to facilitateinsertion of the guidewire into and through the respective axial boresand passageways, and also provide clearances for lips of the valvemembers adjacent their slits 124,128 to be deflected thereinto when,firstly, the centering tool mandrel is being urged through slits 124,128and then withdrawn, and subsequently, a guidewire is being insertedtherethrough or retracted therefrom, and while the guidewire is inposition.

The dimensions or diameters of the respective axial bores andpassageways of the components of the subassembly, and the length of theslits of the valve members, are such as to permit use therewith of arange of guidewire diameters. The material for valve members may be, forexample, silicone, but is preferably, polyisoprene such as Part No.600X600X016-30POE sold by Apple Rubber Products, Inc. of Lancaster, N.Y.Alternatively, other materials may also be utilized. The thickness ofthe valve members is preferably about 0.016 in (0.406 mm), and that thelength of each slit is generally about 0.060 in (1.52 mm). Further, itis preferred that at least 0.010 in (0.254 mm) clearance is providedbetween the edges of each valve member on all sides and the innersurface of valve seat. Preferably, also, the valve members are identicalfor simplification of assembly procedures. Optionally, a small amount ofsilicone oil may be used within the valve seat for lubrication of thevalves that may facilitate insertion, advancement and retraction of theguidewire.

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. For example, the valve seat could be definedin the proximal cap; also, the proximal cap could have a distallyprojecting flange received into a recess of the proximal fitting;further, the valve openings could be a cross-shaped pattern of slits, orother pattern of intersecting slits, or an annular hole of smalldiameter. It is understood, therefore, that this invention is notlimited to the particular embodiments disclosed, but it is intended tocover modifications within the spirit and scope of the present inventionas defined by the appended claims.

What is claimed is:
 1. A method of centering at least one valve within avalve seat of a medical device, comprising the steps of: positioning atleast one valve within the valve seat of the medical device such thateach of the at least one valve is transversely oriented within the valveseat with a diameter less than an inner diameter of the valve seat and acenter opening to be aligned with a passageway of the medical device;positioning a cap on the medical device adjacent the valve seat in aninitial position wherein an aperture defined by the cap is aligned withthe device passageway and the at least one valve adjustably positionedbetween the device and the cap; positioning a mandrel of a centeringtool through the aperture of the cap, through the center opening of theat least one valve and at least partially into the device passagewaysuch that the at least one valve is transversely adjusted to a positionwithin the device wherein the center opening is aligned with the devicepassageway; affixing the cap to the medical device in a second positionsuch that the at least one valve is axially compressed between the capand the device such that the at least one valve is fixed in positionrelative to the valve seat; and withdrawing the centering tool from thedevice.
 2. The method of claim 1, wherein transverse valve-adjacentsurfaces of the device include compression rings that become pressedinto the at least one valve upon complete assembly to securely retainthe at least one valve in position relative to the valve seat uponwithdrawal of the centering tool from the device.